JH._________________"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)

I'd like to use the onboard +/-15V PSU section to power some more modules, but I don't remember (or find) any mentions about this in this thread or at your site. How much current do you think would be possible to squeeze out of this design (with larger heatsinks and possibly some component value changes)?

I'm hoping to use one resonator's PSU to power a compact effect box with two resonators + two 100M M-121 VCFs + two spring reverbs + two Polysix effect boards.

I'd like to use the onboard +/-15V PSU section to power some more modules, but I don't remember (or find) any mentions about this in this thread or at your site. How much current do you think would be possible to squeeze out of this design (with larger heatsinks and possibly some component value changes)?

I'm hoping to use one resonator's PSU to power a compact effect box with two resonators + two 100M M-121 VCFs + two spring reverbs + two Polysix effect boards.

Not calculated, just estimated:

With a 2 * 18V transformer (two secondary windings) and big heat sinks on the regulators, 200mA should be possible.

With *huge* heat sinks and the big electrolytics increased from 470u to 2200u, and bigger rectifier diodes, 1A should be possible.

This is all untested - just applying the general rules of thumb for power supplies.

JH._________________"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)

I'll have a video up soon of mine in its temporary case. I was experimenting with using 2 vactrols in line with the dual pots for the frequency, to get a some sort of primitive voltage control. I'm pretty pleased with the results and encourage others to give it a try. More details soon.

I'll have a video up soon of mine in its temporary case. I was experimenting with using 2 vactrols in line with the dual pots for the frequency, to get a some sort of primitive voltage control. I'm pretty pleased with the results and encourage others to give it a try. More details soon.

-Travis

I was just going to implement the mods by Dave Brown. Did you do this aswell as your own mod? Because it sounds very interesing and if good I will add this to mine.

I was just mulling over something Ken Stone mentioned on the CGS Yahoo list...

If I were to use two 10K pots instead of a 10K stereo pot for the frequency control, would this give me adjustable bandwidth?

This would be interesting in many ways (I guess none of them would be similar to a Polymoog though!) for example voltage control of each (lower and higher range) frequency seperately... (not sure if I'd do that...)

I was just mulling over something Ken Stone mentioned on the CGS Yahoo list...

If I were to use two 10K pots instead of a 10K stereo pot for the frequency control, would this give me adjustable bandwidth?

This would be interesting in many ways (I guess none of them would be similar to a Polymoog though!) for example voltage control of each (lower and higher range) frequency seperately... (not sure if I'd do that...)

hmmmm...

It already has adjustable Bandwidth.

JH._________________"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)

Do you mean the Emphasis control? I thought that would only narrow the bandwidth whilst increasing the Q, whilst I was hoping I could use two seperate knobs to create the base (width) frequency which I could then apply emphasis to...

I guess it wouldn't work then, I was sort of hoping it would as I haven't got my delivery of dual pots yet (they got lost in the Christmas post I think) and I would like to try out the board as soon as possible!

Do you mean the Emphasis control? I thought that would only narrow the bandwidth whilst increasing the Q, whilst I was hoping I could use two seperate knobs to create the base (width) frequency which I could then apply emphasis to...

I guess it wouldn't work then, I was sort of hoping it would as I haven't got my delivery of dual pots yet (they got lost in the Christmas post I think) and I would like to try out the board as soon as possible!

Thanks,

Charlie

These are 2-pole filters, and here, by definition, bandwidth and Q factor are not independent of each other: Q ~ 1/B.

Only with filters of higher order you can create an arbitrary bandwidth, by staggered tuning of partial filters / pole pairs, of which each has its own Q factor.

The only degree of freedom you have in 2-pole filters is Q factor vs. gain, i.e. a choice of compensating the higher gain that normally comes with higher Q (as in the Moog circuit), or not.

Unequal time constants in the two integrator stages will also have an effect on some parameters (don't have my Spice running now), but it won't unlink the bandwidth from Q.

JH._________________"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)

Just found out I ordered a batch of 50K log instead of 10K log, where 5 are specified in the BOM. Can I use the 50K log instead and/or perhaps change a supporting resistor value?_________________Erez Yaary

Just found out I ordered a batch of 50K log instead of 10K log, where 5 are specified in the BOM. Can I use the 50K log instead and/or perhaps change a supporting resistor value?

Should work, but the pot courve will be a little warped.

JH._________________"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)

Can I plug in whatever signal from a commercial synth without modyfing resistor values ?

Naturally, I couldn't have tested every commercial synth, but I wouldn't expect any difficulties.

JH._________________"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)

Waking up groggy from having slept on this one...any boards left? Or anybody with extras?

cool.

I still have boards.

JH._________________"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)

Hello all!
My first post!
I'm a real newbie and need some help with this project. I'm a over my head here. I finished populating the pcb and I'm trying to wire the pots.
I have a couple of supernoob questions. Excuse my ignorance.
The module passes no audio.
1) Could wrong pot wiring do this? I'm testing it right now without the pots for freq and emphasis. I just connected the end of the wires, so that it would work as a pot turned all the way up, correct?
2) Regarding the ICs. The IC's sockets have a cutout in one side. Is that the side where pin 1 goes?
Sorry for the supernoob questions.
Thanks in advance,
Angelo
P.S.
Never mind. I got it. I had it all wired ok. I found an unsoldered resistor leg.
P.P.S.
It works! My first module! Thanks JH!!!
Now I need to figure out why HP and BN are not working.

I've checked all the connections and all the solder points. Everything seems to be correct. The low pass and band pass are working perfectly and sound fantastic. Raw and dirt resonance! Me likes it a lot!!!! But I'm stuck and need some advice. Where should I check? What could be the problem? Bad ICs perhaps?
Please help!
Thanks!!!

I've checked all the connections and all the solder points. Everything seems to be correct. The low pass and band pass are working perfectly and sound fantastic. Raw and dirt resonance! Me likes it a lot!!!! But I'm stuck and need some advice. Where should I check? What could be the problem? Bad ICs perhaps?
Please help!
Thanks!!!

Hi guitarsandsynths,

the problem is that, most likely, there *are* some still undedected errors that don't have much to do with the circuit, but with the soldering, component selection, etc. All I can say is double check (or, triple check) for wrong component values, bad solder joints, shorts from excess solder - that kind of stuff. A bad IC is unlikely if LP and BP functions are working.

JH._________________"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)

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